Wire connecting device



Feb. 13, E. MILLER WIRE CONNECTING DEVICE Filed Nov. 4, 1932 3 "41m M52552 7.5. M/L L 52 Patented Feb. 13, 1934 UNITED STATES PATENT? OFFICE.

This'invention relates to wire connecting devices and particularly to a device for electrically connecting the ends of wires-by clamping them together.

It has been the common practice in the electrical arts for a number of years to provide devices adapted to clamp together the overlaping ends of wires to establish electrical connection therebetween. Such devices find extensive use in electrical industries but have been open to several objections. In the first place, the nature and the extent of the use of such a device demands that it be inexpensive to produce, and most of the devices which have been manufactured for this purpose have been relatively prohibitive in cost. Moreover, most of the devices produced for this purpose in the past have possessed little degree of flexibility as would permit them to snugly engage the wires to form a permanent mechanical connection and to improve the electrical connectionbetween the wires.

An important object of the present invention is to provide a novel form of wire clamp which is comparatively cheap to manufacture and which is highly efiicient in operation.

A further object is to provide a wire clamping device which possesses the inherent flexibility necessary to provide snug distributed engagebetween the wire and to increase the efliciency of the electrical connection therebetween.

A further object is to provide a device of the character referred to wherein a-single clamping member is provided for encircling the overlapping ends of the wires, and wherein the body is drawn into clamping engagement by a threaded member which operates by virtue of the flexibility of the body tocause the latter to snugly en-' gage and embrace the wires. 7

A further object is to provide a wire clamping device having a unitary body formed with a head at one end and a threaded member at the other connected by shank means possessing a substantial degree of flexibility whereby the tightening of a nut on the threaded stem causes the device to alter its shape and thus accommodate itself to the wiresto provide efli'cient mechanicaland electrical connection therebetween.

A further object is to provide a wire clamp of such character as to permit each size to ac-' Other objects and advantages or the invention will become apparent during the course of i the following description.

In the drawing I have shown one embodiment of the invention. In this showing:

Figure 1 is a face View of the device in open position,

Figure 2 is a side elevation of the same,

Figure 3 is a section on line 3-3 of Figure 2,

Figure 4 is a side elevation of the clamp in operative position,

Figure 5 is a rear elevation of a modified form of the apparatus, and,

Figure 6 is a side elevation of the same showing the operative position of the parts in dotted lines.

Referring to Figures 1 to 4 inclusive, the numeral l0 designates the clamp body as a whole including a head 11, connecting shank 12 and threaded stem 13. The entire device obviously is made of metal, and is preferably formed of a metal possessing a substantial degree of electrical conductivity and which is relatively soft. In practice it has been found that copper is the most eflicient metal to employ in the formation of the body.

Referring to Figures 1, 2 and 3 it will be noted that the shank 12 is formed of a plurality of laminae comprising flat metal sheets of substantial width, as shown in Figure l. The reason for employing laminations in forming the shank 12 will be apparent. The upper ends of the laminations, of the shank 12 are curved as at for connection with the head 11, and such connection is preferably formed by butt welding the parts to each other. In this connection attention is invited to the fact that the head 11 preferably is formed by forging and accordingly is capable of being pro duced at a low cost.

The lower end of the shank 12 also is preferably butt welded to the upper end of the threaded stem 13. As shown in Figure 1, the lower ends of the laminations 14 decrease in width as at 16 toward the stem 13, while the upper end of the stem is tapered inwardly as at 17 whereby the width of the stem at its upper end coincides with the thickness of the shank 12. The threaded stem 13 is adapted to be received in a nut 14 to be described in detail later.

As shown in Figures 1 and 3, the head 11 is bifurcated as at 18 to form a space for receiving the stem 13 when the device is to be clamped in position around the ends of electric wires 19 as shown in Figure 4. The head 11 is provided with depending fingers or prong members 20 on opposite sides of the opening 18, and the inner faces 21 of the depending fingers are perfectly flat and lie in a common plane parallel to the straight portion of the shank 12. The upper ends of the inner faces 21 curve to merge in substantially semicylindrical form with the inner face of the adjacent portion of the shank 12 as indicated at 22.

The upper portion of the head 11 is substantially circular in plan except for the cutaway portion 18, and is preferably hemispherical in shape. The lower face of the fingers 21 preferably extend upwardly and outwardly, as at 23 to the free ends of the opposite sides of the head 11 defined by the cutout portion 18. The nut 14 is provided with a substantially hemispherical recess 24, as shown in Figure 4.

In Figures 5 and 6 of the drawing-a somewhat modified form of the invention has been illustrated. In such form, a head 25 is employed, the upper face of which is substantially hemispherical as in the case of the head 11, and is provided with depending fingers 26 having their inner faces 2'? arranged to correspond to the faces 21 of the-fingers 20. The lower outer faces of the fingers 26 also preferably are inclined upwardly as at 28 for a purpose to be described.

The opposite end of the modified form of the device also is provided with a threaded stem 29, similar to the stem 13, and the connecting member or shank is in the form of a relatively flat chain 30 made up of a plurality of relatively small links 31 pivotally connected to each other as at 32. The uppermost series of links is pivotally connected to the head 25 as at 33 while the lowermost series of links is connected to the upper end of the shank 29 as at 34. The chain 30 obviously permits the stem 29 to be swung upwardly to the dotted line position shown in Figure 6, and the head 25 is bifurcated similar to the head 11 to form arms between which the stem 29 may be arranged. A nut 35 is adapted to be threaded on the stem as shown in dotted lines in Figure 6, and this nut is identical with the nut 14 previously described.

The operation of the form of the invention shown in Figures 1 to 4 inclusive is as follows. As previously stated, the entire device is made of a relatively soft metal of high electrical conductivity and accordingly copper is preferably employed. The formation of the shank 12 in laminated form provides a high degree of flexibility in the shank without any sacrifice of the necessary tensile strength. When the device is to be assembled, the wires to be connected'are arranged with their ends in overlapped posi-- tion, and such ends are placed in the recess defined by the parallel faces of the fingers 20 and shank 12 with the uppermost wire arranged against the curved face portion 22. As will become apparent, the wire need not coincide exactly in size to the semi-circular face 22, since the device is adapted to accommodate wires of different sizes within the reasonable limits. v

After the wires have been placed in the position described, the operator moves the shank 13 toward the head 11, thus bending the shank 12 which action is readily permitted by virtue of the flexibility of the shank. With the stem 13 arranged in the cutout portion 18, the nut 14 is-applied on the upper end of the stem 13 and tightened. v

It will be apparent that the end of the shank this arrangement is highly important for several reasons. In the first place, such engagement of the shank and the inclined faces 23 tends to prement with the wires. tion, through the flexibility of the shank 12,

vent the stem 13 from moving into tight engagement with the inner extremity of the cutout portion 18 which would cause binding of the stem 13 and render it diificult to draw the stem upwardly as the nut is tightened. Moreover, the shank 12 is relatively wide and the engagement of the end portion thereof with the faces 23 tends to prevent turning or twisting of the stem 13 as the nut is tightened. Moreover, the inclined face 23 causes the adjacent end of the shank 12 to move upwardly and away from the wires 19 as the nut is tightened, thus drawing the shank 12 into snug engagement with the wires and at the same time holding the faces 21 in engage- Thus the tightening accauses the device to accommodate itself to the shape of the' wires 19 to snugly engage the latter and thus provide an eflicient mechanical and electrical engagement. The wires themselves, of course, will be held in firm engagement with each other.

As the tightening action of the nut progresses, the stem 13 tends to alter its position slightly with respect to the head 11. The formation of the "substantially hemispherical engaging faces of the nut 14 and head 11 permit these elements to alter their positions with respect to each other and still retain engagement throughout surfaces surrounding the stem 13. This arrangement prevents the pressure incident to the tightening action of the head from being exerted against one side of the latter, and accordingly the nut is'prevented from binding on the stem 13. The various features referred to accordingly permit the nut to-bedrawn tightly against the head 11 and an efficient clamping engagement thus is provided to form a permanent mechanical and electrical connection between the wires.

The form of the invention shown in Figures 5 and 6 operates in the same manner as the form previously described except that a higher degree of flexibility in the shank or connecting member is-provided by employing the flexible chain 30. The end portion of the chain adjacent the stem 29 engages the inclined face 28 to accomplishthe results described above. When the chainis employed, such member may be formed of a material having a higherdegree of structural strength than copper, and may be coated with copper orsimilar metal to increase the efficiency oftheelectrical connection between the chain and the wires.

Thepresent device-largely eliminates the machining operations which-have been -performed on previousdevicesof this character, and accordingly the device may be produced at a low cost. Further reductions in the cost are possible due to the reduction in the number of parts employed as compared with most of the previous devices of this character. The flexibility of the shank or connectingmember and taken'as preferredexamples of 'thesame and that various changes in the shape, size and arrangement of parts may" beresorted towithout departing from the spirit of the invention or the scope of the subjoined claims.

I claim:

1. A wire clamp comprising a relatively wide flexible shank, a head carried by one end of said shank and provided with a depending portion spaced from and parallel to a portion of said shank to form a wire receiving space, a threaded stem carried by the other end of said shank, said head being bifurcated to form a cut out portion to receive said stem when said shank is bent around the wires in said space, and a nut threaded on said stem and movable thereon in engagement with said head to contract said shank around the wires, said depending portion having an upwardly and outwardly inclined lower face engageable with the last named end of said shank when the latter is bent around the wires.

2. A wire clamp comprising a relatively wide flexible shank, a head carried by one end of said shank and provided with a depending portion spaced from and parallel to a portion of said shank to form a wire receiving space, a threaded stem carried by the other end of said shank, said head being bifurcated to form a cut out portion to receive said stem when said shank is bent around the wires in said space, and a nut threaded on said stem and movable thereon in engagement with said head to contract said shank around the wires, said depending portion having an upwardly and outwardly inclined lower face engageable with the last named end of said shank when the latter is bent around the wires, said nut and said head having contacting faces forming sections of a sphere.

3. A wire clamp comprising a relatively wide shank formed of laminations of a relatively soft metal, a head permanently joined to one end of said shank and provided with a depending portion spaced from and parallel to said shank to form a wire engaging space, said head being bifurcated to form a cut out portion, a threaded stem carried by the other end of said shank and movable into said out out portion when said shank is bent around the Wires in said space, and a nut threaded on said stem and engageable with said head, said nut and said head being provided with coinciding contacting surfaces forming a section of a sphere.

4. A wire clamp comprising a relatively wide shank formed of laminations of a relatively soft metal, a head permanently joined to one end of said shank and provided with a depending portion spaced from and parallel to said shank to form a wire engaging space, said head being bifurcated to form a cut out portion, a threaded stem carried by the other end of said shank and movable into said out out portion when said shank is bent around the wires in said space, and a nut threaded on said stem and engageable with said head, said nut and said head being provided with coinciding contacting surfaces forming a section of a sphere, the depending portion of said head having an upwardly and outwardly inclined lower face engageable by the last named end of said shank when said stem is moved into said out out portion.

5. A wire clamp comprising a shank formed of a plurality of pivotally connected links, a head pivotally connected to one end of said shank and bifurcated to form a cut out portion, said head being provided with a depending portion having 105 one face arranged parallel to a portion of said shank to form a wire receiving space, a threaded stem carried by the other end of said shank and movable into said out out portion when said shank is turned about the wires in said space, 110 and a nut threaded on said stem and engageable with said head for contracting said shank around the wires, said head being provided with a lower face inclined upwardly and outwardly away from the wires and engageable with the 115 last named end of said shank.

HERBERT E. MILLER. 

